Abnormal cortical complexity and thickness profiles mapped in Williams syndrome
ABSTRACT We identified and mapped an anatomically localized failure of cortical maturation in Williams syndrome (WS), a genetic condition associated with deletion of approximately 20 contiguous genes on chromosome 7. Detailed three-dimensional (3D) maps of cortical thickness, based on magnetic resonance imaging (MRI) scans of 164 brain hemispheres, identified a delimited zone of right hemisphere perisylvian cortex that was thicker in WS than in matched controls, despite pervasive gray and white matter deficits and reduced total cerebral volumes. 3D cortical surface models were extracted from 82 T1-weighted brain MRI scans (256 x 192 x 124 volumes) of 42 subjects with genetically confirmed WS (mean +/- SD, 29.2 +/- 9.0 years of age; 19 males, 23 females) and 40 age-matched healthy controls (27.5 +/- 7.4 years of age; 16 males, 24 females). A cortical pattern-matching technique used 72 sulcal landmarks traced on each brain as anchors to align cortical thickness maps across subjects, build group average maps, and identify regions with altered cortical thickness in WS. Cortical models were remeshed in frequency space to compute their fractal dimension (surface complexity) for each hemisphere and lobe. Surface complexity was significantly increased in WS (p < 0.0015 and p < 0.0014 for left and right hemispheres, respectively) and correlated with temporoparietal gyrification differences, classified via Steinmetz criteria. In WS, cortical thickness was increased by 5-10% in a circumscribed right hemisphere perisylvian and inferior temporal zone (p < 0.002). Spatially extended cortical regions were identified with increased complexity and thickness; cortical thickness and complexity were also positively correlated in controls (p < 0.03). These findings visualize cortical zones with altered anatomy in WS, which merit additional study with techniques to assess function and connectivity.
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ABSTRACT: Congenital amusia is defined by marked deficits in pitch perception and production. Though historically examined only in otherwise typically developing (TD) populations, amusia has recently been documented in Williams syndrome (WS), a genetic, neurodevelopmental disorder with a unique auditory phenotype including auditory sensitivities and increased emotional responsiveness to music but variable musical skill. The current study used structural T1-weighted magnetic resonance imaging and diffusion tensor imaging to examine neural correlates of amusia in 17 individuals with WS (4 of whom met criteria for amusia). Consistent with findings from TD amusics, amusia in WS was associated with decreased fractional anisotropy (FA) in the right superior longitudinal fasciculus (SLF). The relationship between amusia and FA in the inferior component of the SLF was particularly robust, withstanding corrections for cognitive functioning, auditory sensitivities, or musical training. Though the number of individuals with amusia in the study is small, results add to evidence for the role of fronto-temporal disconnectivity in congenital amusia and suggest that novel populations with developmental differences can provide a window into understanding gene-brain-behavior relationships that underlie musical behaviors.12/2014; 4(4):594-612. DOI:10.3390/brainsci4040594
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ABSTRACT: The head circumference growth reference charts for children in China are presently based on urban children. However, the references may not apply to rural children because of the differences between urban and rural areas, such as economy, culture, and dietary habits. Our objective was to provide a reliable continuous set of head circumference growth reference charts for male and female children less than 7 years of age in Chinese rural areas. Children in our study were identified by multistage stratified cluster sampling from rural areas of 10 provinces in China. Questionnaire survey and anthropometric measurements were conducted in data collection. Head circumference was measured with a nonelastic tape on a line passing over the glabella and posterior occipital protrusion in children. We compared the fiftieth percentile of our cross-sectional data with the data of Chinese cities, World Health Organization, and the United States. A total of 95,904 children (48,722 boys and 47,182 girls) were included in the study. We present age- and sex-appropriate head circumference growth charts younger than 7 years for Chinese rural areas. The head circumference percentiles of the children in rural China are much smaller than the children in Chinese urban areas, World Health Organization, and the US percentiles after 2 years old. Head circumference percentiles can be applied in growth monitoring, but current head circumference growth references promulgated in urban China may not be suitable for rural areas in China. Providing head circumference growth reference charts for rural Chinese children who are younger than 7 years old is very important. Copyright © 2014 Elsevier Inc. All rights reserved.Pediatric Neurology 12/2014; 51(6):814-9. DOI:10.1016/j.pediatrneurol.2014.08.014 · 1.50 Impact Factor
Article: The Eye of the Beholder.APS observer 01/2007; 20(1):5-44.